There are millions of fluorescent light tube troffers/fixtures installed every year, providing both task and general lighting within schools, offices, hospitals, and retail stores. Accordingly, the advent of the fluorescent light tube troffer/fixture has shown to be a significant improvement over incandescent light fixtures within the prior art.
The traditional fluorescent light tube troffer/fixture containing fluorescent light tubes and an electronic ballast have common drawbacks of high power consumption, short service life, and a somewhat fragile structure. Another drawback is their use of rare-earth and other toxic phosphors needed to generate light. This presents a problem when the tubes which have ceased to function require disposal. The phosphors within a fluorescent light tube may present a hazardous waste situation which must be dealt with.
There are a number of patents describing an LED base light source as one way to replace fluorescent light tubes. LED replacement tubes typically contain a transparent tube with LED's mounted inside the tube, and dual end caps, wherein each end cap is mounted at a respective end of the light tube. Both end caps each typically contain a pair of conductive prongs functioning as connectors so that the tube may be inserted into respective sockets within a fluorescent tube troffer, for example, thereby electronically communicating with the electronic ballast system of the fluorescent troffer. These LED replacement light tubes are therefore intended for retrofitting into an existing fluorescent light troffer/fixture. As such, the use of LED replacement light tubes within a new troffer/fixture would be one way of incorporating LEDs into new troffer/fixture, but it may be costly. One reason the LED replacement tubes cost more is the additional circuitry. For example, an AC to DC converter is typically incorporated within the tube increasing the cost of the LED replacement tube. Using known LED replacement tubes within a new or used troffer will also require conductive sockets at both ends of the troffer resulting in additional wiring and labor costs.
High bay fluorescent light fixtures are widely currently used as are the drop-in fluorescent troffers. The high bay fluorescent light fixture does not have a cover whereas the drop-in fluorescent troffers typically have a cover. Both types of troffers typically contain two to four fluorescent light tubes and are powered by a conventional fluorescent ballast. These fluorescent light tube fixtures/troffers have been used for decades. The exemplary two-foot by four-foot fluorescent light tube troffer is powered by AC energy and is activated by power from a wall switch. Light manufacturers, architects, and contractors are now oftentimes replacing the traditional fluorescent light troffer with a new troffer/fixture featuring LEDs as the preferred light source because of their longevity and relatively greater energy efficiency.
Another concern with the traditional fluorescent tube troffer is the complexity of its assembly. The fluorescent tube troffer requires an electronic ballast to power the fluorescent tubes and extensive wiring is required to connect the electronic ballast to the socket holders at both ends of the troffer resulting in a relatively higher overall cost.
Architects, homeowners, and contractors are therefore in need of a troffer/fixture similar in design, size and shape of a traditional fluorescent light tube fixture/troffer and offers LEDs as its light source. More importantly, a new troffer or fixture that provides power to operate a DC power LED light source (instead of the more expensive AC powered LED light tube replacement), reduces the replacement cost of the LED light source when the LEDs fails.